⇒ Junior is applied to distinguish the younger of two persons bearing the same name in the same family, and is opposed to senior or elder. Commonly applied to a son who has the same Christian name as his father.

2.

Lower in standing or in rank; later in office; as, a junior partner; junior counsel; junior captain.

3.

Composed of juniors, whether younger or a lower standing; as, the junior class; of or pertaining to juniors or to a junior class. See Junior, n., 2.

Hence: One of a lower or later standing; specifically, in American colleges, one in the third year of his course, one in the fourth or final year being designated a senior; in some seminaries, one in the first year, in others, one in the second year, of a three years' course.